In recent years, liquid crystal displays, organic electroluminescent displays, MEMS and the like are widely used as display devices of electronic devices such as smartphones, personal assistant devices (PAD) and tablet computers. These display devices usually include a glass substrate having a display area and one or more driver ICs (drive circuitries) mounted on the glass substrate in an outer portion of the display area by a COG technology or the like. A driver IC drives a large number of pixels which constitute the display area.
In more recent years, as the display devices are enlarged in size, their resolutions are enhanced and the number of additional features is increased, the amount of current flowing the drivers IC increases, which may cause an increase in the heat generation of driver ICs.